Active alignment system and active alignment method

Abstract

The present application provides an active alignment system and an active alignment method for assembling a laser module. The active alignment system comprises a positioning unit, a sensing unit and a control unit electrically connected between the positioning unit and the sensing unit. The sensing unit is used to sense a measured pattern obtained by a laser beam passing through an optical lens. The control unit is used to drive the positioning unit to move the optical lens until the measured pattern meets a detection standard according to the measured pattern. The present application has the advantages of improving the manufacturing precision of the laser module and reducing the manufacturing cost, and is suitable for mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optics, and in particular to an active alignment system and an active alignment method. BACKGROUND

[0002] Due to the high photoelectric conversion efficiency of laser light sources, and the optical characteristics of laser beams output by laser light sources, such as high energy, consistent wavelength, single frequency, and good collimation, laser light sources are gradually being widely used. Referring to Figure 1 and Figure 2 , Figure 1 is a cross-sectional conceptual diagram of part of the structure of a conventional laser module, Figure 2 is Figure 1 a perspective exploded diagram of part of the structure of the laser module shown in FIG. 1. The conventional laser module 1 includes a housing 10, an inner housing 11, a substrate 12, a laser unit 13, a reflective optical element 15, a collimating optical element 16, a diffractive optical element (DOE) 17, and a ceramic plate 14, and the substrate 12 is used to support the laser unit 13, the ceramic plate 14, the housing 10, and the inner housing 11, and the laser unit 13 is disposed on the ceramic plate 14 to be electrically connected to the substrate 12; wherein the inner housing 11 is disposed in the accommodation space of the housing 10, and the collimating optical element 16 and the diffractive optical element 17 are fixed on the inner housing 11 and the housing 10, respectively, so that the collimating optical element 16 is located between the substrate 12 and the diffractive optical element 17 in the vertical direction.

[0003] Furthermore, when the laser unit 13 receives power, the laser unit 13 can provide a plurality of laser beams L1, and the laser beams L1 travel in the direction of the reflective optical element 15, and after being projected onto the reflective optical element 15, they are reflected by the reflective optical element 15 to travel in the direction of the collimating optical element 16 and the diffractive optical element 17. The collimating optical element 16 is used to collimate the laser beams L1 reflected by the reflective optical element 15, so that the laser beams L1 passing through the collimating optical element 16 are incident on the diffractive optical element 17 in a better incident direction, and the diffractive optical element 17 is used to perform beam shaping on the laser beams L1 passing through the collimating optical element 16, so that the laser beams L1 form structured light and are projected outward.

[0004] Especially, the laser module 1 has many parts, which increases the complexity of assembly and becomes a barrier to improve the assembly precision. For example, when the collimating optical element 16 is fixed on the reflecting optical element 15 during the assembly of the laser module 1, the positioning deviation may occur. When the diffractive optical element 17 is fixed on the collimating optical element 16, the positioning deviation may also occur. Obviously, the stacking of each element will cause the overall deviation to continuously expand, and the precision is only about micron level, so that the structured light projected by the laser module 1 cannot meet the actual use requirements.

[0005] The existing correction method is to cut the bottom of the carrier (i.e. the inner shell 11) carrying the collimating optical element 16 by micro machining (i.e. mechanical cutting), so that the collimating optical element 16 is located at the focusing position and attitude. Similarly, the bottom of the carrier (i.e. the outer shell 10) carrying the diffractive optical element 17 is also cut by micro machining (i.e. mechanical cutting), so that the diffractive optical element 17 is located at the focusing position and attitude. However, the precision that can be improved by the above-mentioned micro machining (i.e. mechanical cutting) is still limited, and is about micron level, and needs to be processed by a very expensive precision machining machine, and is not suitable for mass production. SUMMARY

[0006] The technical problem to be solved by the present application is to provide an active alignment system for assembling a laser module, thereby improving the manufacturing precision of the laser module and reducing the manufacturing cost, and being suitable for mass production.

[0007] The technical problem to be solved by the present application is to provide an active alignment method for assembling a laser module, thereby improving the manufacturing precision of the laser module and reducing the manufacturing cost, and being suitable for mass production.

[0008] The technical solution adopted by the present application to solve the technical problem is to provide an active alignment system for assembling a laser module, the laser module comprising at least one optical lens and a laser unit, and a laser beam generated by the laser unit is projected outward after passing through the at least one optical lens, wherein the active alignment system comprises: a positioning unit for moving the at least one optical lens; a first sensing unit for sensing the laser beam passing through the at least one optical lens to obtain a measured pattern; and a control unit electrically connected between the positioning unit and the first sensing unit, for driving the positioning unit to move the at least one optical lens until the measured pattern meets a detection standard according to the measured pattern.

[0009] In a preferred embodiment, the laser module further comprises a reflective optical element, and the laser unit is a side emitting laser unit; wherein the reflective optical element is used to reflect the laser beam generated by the side emitting laser unit so that the laser beam travels towards the at least one optical lens.

[0010] In a preferred embodiment, the laser unit is a vertical cavity surface emitting laser (VCSEL), and the laser beam generated by the vertical cavity surface emitting laser travels towards the at least one optical lens.

[0011] In a preferred embodiment, the positioning unit is a six-axis positioning unit.

[0012] In a preferred embodiment, the at least one optical lens comprises a collimating optical element, and the collimating optical element is used to collimate the laser beam passing through the collimating optical element.

[0013] In a preferred embodiment, the detection criteria comprises a spot size detection criterion, a spot shape detection criterion, and / or a spot position detection criterion.

[0014] In a preferred embodiment, the first sensing unit is a beam profiler.

[0015] In a preferred embodiment, the laser module further comprises an inner housing, and the inner housing is used to allow the collimating optical element to be disposed thereon; wherein the positioning unit moves the collimating optical element by moving the inner housing.

[0016] In a preferred embodiment, the active alignment system further comprises a second sensing unit electrically connected to the control unit and used to take a picture of the collimating optical element; wherein the control unit is further used to drive the positioning unit to move the collimating optical element to a standard position and a standard attitude with the location of the laser unit as the positioning reference, according to a picture taken by the second sensing unit.

[0017] In a preferred embodiment, the laser module further comprises an inner housing, and the inner housing is used to allow the collimating optical element to be disposed thereon; wherein the positioning unit moves the collimating optical element by moving the inner housing.

[0018] In a preferred embodiment, the collimating optical element is first moved by the positioning unit to a predetermined position and a predetermined attitude with a system self-defined reference standard as the positioning reference, and then placed on the inner housing by the positioning unit.

[0019] In a preferred embodiment, the second sensing unit includes at least three cameras, and the at least three cameras are respectively located in different directions of the collimating optical element.

[0020] In a preferred embodiment, the at least one optical lens includes a diffractive optical element (DOE) for beam shaping the laser beam passing therethrough, so as to form a structured light.

[0021] In a preferred embodiment, the detection criteria include a dot count detection criterion, a contrast detection criterion, an illumination field of view detection criterion, a hotspot detection criterion, a pattern angle detection criterion, a zero order detection criterion, a power uniformity detection criterion, and / or a geometrical & pattern mass center detection criterion.

[0022] In a preferred embodiment, the first sensing unit includes a projection surface and a camera module, and the projection surface is disposed between the DOE and the camera module; wherein the camera module photographs to obtain the measured pattern when the structured light is projected onto the projection surface.

[0023] In a preferred embodiment, the laser module further includes an outer housing, and the DOE is disposed on the outer housing; wherein the positioning unit moves the DOE by moving the outer housing.

[0024] In a preferred embodiment, the active alignment system further includes a second sensing unit electrically connected to the control unit and used for photographing the DOE; wherein the control unit is further used for driving the positioning unit to move the DOE to a standard position and a standard posture according to a photographing result of the second sensing unit.

[0025] In a preferred embodiment, the at least one optical lens further includes a collimating optical element below the DOE, and the laser module further includes an inner housing for disposing the collimating optical element thereon; wherein the control unit is used for driving the positioning unit to move the DOE to the standard position and the standard posture with the inner housing and / or the collimating optical element as a positioning reference according to the photographing result of the second sensing unit.

[0026] In a preferred embodiment, the second sensing unit includes at least three cameras, and the at least three cameras are respectively located in different directions of the diffractive optical element.

[0027] In a preferred embodiment, the laser module further includes a housing, and the housing is used for disposing the diffractive optical element thereon; wherein the positioning unit moves the diffractive optical element by moving the housing.

[0028] In a preferred embodiment, the second sensing unit photographs the housing for subsequent housing surface analysis.

[0029] In a preferred embodiment, the active alignment system further includes at least one mirror element, and the at least one mirror element is disposed adjacent to the housing; wherein the second sensing unit photographs the housing and / or the at least one mirror element for subsequent housing surface analysis.

[0030] In a preferred embodiment, the diffractive optical element is first moved by the positioning unit to a predetermined position and a predetermined posture with a system self-defined reference standard as a positioning reference, and then placed on the housing by the positioning unit.

[0031] The present disclosure also provides an active alignment method for assembling a laser module, the laser module including at least one optical lens and a laser unit, and a laser beam generated by the laser unit is projected outward after passing through the at least one optical lens, wherein the active alignment method includes:

[0032] (a) sensing the laser beam passing through the at least one optical lens to obtain a measured pattern; and

[0033] (b) moving the at least one optical lens according to the measured pattern until the measured pattern meets a detection standard.

[0034] In a preferred embodiment, the laser module further includes a reflective optical element, and the laser unit is an edge-emitting laser unit; wherein the reflective optical element is used to reflect the laser beam generated by the edge-emitting laser unit so that the laser beam travels in the direction of the at least one optical lens.

[0035] In a preferred embodiment, the laser unit is a vertical cavity surface emitting laser (VCSEL), and the laser beam generated by the vertical cavity surface emitting laser travels in the direction of the at least one optical lens.

[0036] In a preferred embodiment, the step (b) comprises moving the at least one optical lens by using a six-axis positioning unit.

[0037] In a preferred embodiment, the at least one optical lens comprises a collimating optical element, and the collimating optical element is used to collimate the laser beam passing through the collimating optical element.

[0038] In a preferred embodiment, the detection criteria comprises a light spot size detection criterion, a light spot shape detection criterion, and / or a light spot position detection criterion.

[0039] In a preferred embodiment, the step (a) comprises sensing the laser beam passing through the collimating optical element by using a beam profiler.

[0040] In a preferred embodiment, the laser module further comprises an inner housing, and the inner housing is used to set the collimating optical element thereon; wherein in the step (b), the collimating optical element is moved by moving the inner housing.

[0041] In a preferred embodiment, the active alignment method further comprises, before the step (a):

[0042] (c1) photographing the collimating optical element;

[0043] (c2) moving the collimating optical element according to a photographing result until the collimating optical element is located at a standard position and in a standard attitude with the location of the laser unit as a reference.

[0044] In a preferred embodiment, the step (c1) comprises photographing the collimating optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element.

[0045] In a preferred embodiment, the step (c2) comprises moving the collimating optical element by using a six-axis positioning unit.

[0046] In a preferred embodiment, the laser module further comprises an inner housing, and the inner housing is used to set the collimating optical element thereon; wherein in the step (c2), the collimating optical element is moved by moving the inner housing.

[0047] In a preferred embodiment, the active alignment method further comprises, before the step (c1):

[0048] (d1) photographing the collimating optical element;

[0049] (d2) moving the collimating optical element according to a shooting result obtained in the step (d1) until the collimating optical element is located at a predetermined position and in a predetermined posture with a system self-defined reference standard as a positioning reference;

[0050] (d3) shooting the collimating optical element and the inner housing; and

[0051] (d4) moving the collimating optical element according to a shooting result obtained in the step (d3) so as to align the collimating optical element with the inner housing and place the collimating optical element on the inner housing.

[0052] In a preferred embodiment, the step (d1) comprises: shooting the collimating optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element.

[0053] In a preferred embodiment, the step (d2) and / or the step (d4) comprises: moving the collimating optical element by using a six-axis positioning unit.

[0054] In a preferred embodiment, the at least one optical lens comprises a diffractive optical element (DOE) for beam shaping the laser beam passing therethrough so as to form a structured light.

[0055] In a preferred embodiment, the detection standard comprises a dot count detection standard, a contrast detection standard, an illumination field of view detection standard, a hotspot detection standard, a pattern angle detection standard, a zero order detection standard, a power uniformity detection standard and / or a geometrical & pattern mass center detection standard.

[0056] In a preferred embodiment, the step (a) comprises: shooting by using a camera module to obtain the measured pattern when the structured light is projected to a projection surface.

[0057] In a preferred embodiment, the laser module further comprises an outer housing, and the outer housing is used for disposing the diffractive optical element thereon; wherein in the step (b), the diffractive optical element is moved by moving the outer housing.

[0058] In a preferred embodiment, the active alignment method further comprises, before the step (a):

[0059] (e1) photographing the diffractive optical element;

[0060] (e2) moving the diffractive optical element according to a photographing result until the diffractive optical element is located at a standard position and is in a standard posture.

[0061] In a preferred embodiment, the at least one optical lens further comprises a collimating optical element located below the diffractive optical element, and the laser module further comprises an inner housing for the collimating optical element to be disposed thereon; wherein the step (e2) comprises: moving the diffractive optical element according to the photographing result until the diffractive optical element is located at the standard position with the inner housing and / or the collimating optical element as the positioning reference and is in the standard posture.

[0062] In a preferred embodiment, the step (e1) comprises: photographing the diffractive optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the diffractive optical element.

[0063] In a preferred embodiment, the step (e2) comprises: moving the diffractive optical element by using a six-axis positioning unit.

[0064] In a preferred embodiment, the laser module further comprises an outer housing, and the outer housing is for the diffractive optical element to be disposed thereon; wherein, in the step (e2), the diffractive optical element is moved by moving the outer housing.

[0065] In a preferred embodiment, the active alignment method further comprises, before the step (e2):

[0066] (f1) photographing the diffractive optical element;

[0067] (f2) moving the diffractive optical element according to a photographing result obtained in the step (f1) until the diffractive optical element is located at a predetermined position with a system self-defined reference standard as the positioning reference and is in a predetermined posture;

[0068] (f3) photographing the diffractive optical element and the outer housing; and

[0069] (f4) moving the diffractive optical element according to a photographing result obtained in the step (f3) so that the diffractive optical element is aligned with and disposed on the outer housing.

[0070] In a preferred embodiment, the step (f1) comprises: photographing the diffractive optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the diffractive optical element.

[0071] In a preferred embodiment, step (f2) and / or step (f4) includes: moving the diffractive optical element using a six-axis positioning unit.

[0072] In a preferred embodiment, the active alignment method further includes, before step (a), performing an adhesive application, and after step (b), performing a curing process on the adhesive applied in the adhesive application.

[0073] This invention utilizes an optical active alignment method to position and correct the position and orientation of optical lenses during the assembly of laser modules, which can significantly improve the assembly accuracy of laser modules and reduce assembly costs, making it suitable for mass production. Attached Figure Description

[0074] Figure 1 This is a cross-sectional conceptual diagram of a portion of the structure of a known laser module.

[0075] Figure 2 :for Figure 1 A three-dimensional exploded view of part of the structure of the laser module shown.

[0076] Figure 3 : A cross-sectional conceptual diagram of a laser module assembled using the active alignment system and active alignment method of the present invention in a preferred embodiment.

[0077] Figure 4 :for Figure 3 A three-dimensional exploded view of part of the structure of the laser module shown.

[0078] Figure 5 : This is a block concept diagram of a preferred embodiment of the active alignment system of the present invention.

[0079] Figure 6A : for use Figure 5 The diagram shows a first-stage implementation concept of the active alignment system assembling collimating optical elements onto the inner housing.

[0080] Figure 6B : for use Figure 5 The diagram shows a second-stage implementation concept of the active alignment system, which assembles the collimating optical element onto the inner housing.

[0081] Figure 7A : for use Figure 5 The diagram shows a preferred embodiment of an active alignment system for coarse positioning of an optical element.

[0082] Figure 7B : for use Figure 5A preferred embodiment of the active alignment system for fine positioning and assembling the collimating optical element to the laser module.

[0083] Figure 8A A preferred embodiment of the test pattern when the collimating optical element is at the in-focus position and orientation.

[0084] Figure 8B A preferred embodiment of the test pattern when the collimating optical element is at the in-focus position and orientation.

[0085] Figure 9A A preferred embodiment of the active alignment system for coarse positioning the diffractive optical element. Figure 5 A first stage of the active alignment system for assembling the diffractive optical element to the housing.

[0086] Figure 9B A second stage of the active alignment system for assembling the diffractive optical element to the housing. Figure 5 A preferred embodiment of the active alignment system for coarse positioning the diffractive optical element.

[0087] Figure 10A A preferred embodiment of the active alignment system for fine positioning and assembling the diffractive optical element to the laser module. Figure 5 A preferred embodiment of the active alignment system for fine positioning and assembling the diffractive optical element to the laser module.

[0088] Figure 10B A preferred embodiment of the active alignment system for fine positioning and assembling the diffractive optical element to the laser module. Figure 5 A preferred embodiment of the active alignment system for fine positioning and assembling the diffractive optical element to the laser module.

[0089] Figure 11 A preferred embodiment of the test pattern when the diffractive optical element is at the in-focus position and orientation.

[0090] Figure 12 A preferred block flow diagram of the active alignment method.

[0091] Figure 13A A preferred block flow diagram of the active alignment method.

[0092] Figure 13B A preferred block flow diagram of the active alignment method.

[0093] Figure 14 A preferred block flow diagram of the active alignment method.

[0094] Figure 15 A preferred embodiment of the laser module assembled with the active alignment system and the active alignment method. DETAILED DESCRIPTION

[0095] Embodiments of the present application will be further explained with reference to the following drawings. Wherever possible, corresponding reference numbers are used throughout the drawings and specification. In the drawings and specification, like reference numbers will be used to refer to like or similar elements. In the drawings, the shapes and thicknesses of components can be exaggerated for clarity. It should be understood that elements shown or described as part of one embodiment can be used in other embodiments as well. It is to be understood that other specific arrangements can be utilized and that the generic or specific arrangement described or shown will be utilized or combined or replaced in other embodiments.

[0096] First, a laser module assembled by the active alignment system and the active alignment method of the present application is described. Please refer to FIG. 1, which is a perspective view of a laser module 2 according to a preferred embodiment of the present application. The laser module 2 includes an outer housing 20, an inner housing 21, a substrate 22, a laser unit 23, a ceramic plate 24, a reflective optical element 25, a collimating optical element 26, and a diffractive optical element (DOE) 27. The substrate 22 is used to support the laser unit 23, the ceramic plate 24, the outer housing 20, and the inner housing 21. The laser unit 23 is disposed on the ceramic plate 24 to be electrically connected to the substrate 22. The inner housing 21 is disposed in a receiving space of the outer housing 20. The collimating optical element 26 and the diffractive optical element 27 are fixed on the inner housing 21 and the outer housing 20, respectively, such that the collimating optical element 26 is located between the substrate 22 and the diffractive optical element 27 in a vertical direction. Figure 3 and Figure 4 , Figure 3 FIG. 2 is a cross-sectional view of a partial structure of the laser module 2 according to the preferred embodiment of the present application. The laser unit 23 is a side-firing laser unit. When the laser unit 23 receives power, the laser unit 23 can provide a plurality of laser beams L2. The laser beams L2 travel toward the reflective optical element 25 and are reflected by the reflective optical element 25 toward the collimating optical element 26 and the diffractive optical element 27. The collimating optical element 26 collimates the laser beams L2 reflected by the reflective optical element 25 so that the laser beams L2 passing through the collimating optical element 26 are incident on the diffractive optical element 27 in a preferred direction. The diffractive optical element 27 reshapes the laser beams L2 passing through the collimating optical element 26 so that the laser beams L2 form structured light and are projected outward. Figure 4 for Figure 3 FIG. 3 is an exploded view of the partial structure of the laser module 2 shown in FIG. 2. The laser unit 23 is disposed on the ceramic plate 24 to be electrically connected to the substrate 22. The inner housing 21 is disposed in the receiving space of the outer housing 20. The collimating optical element 26 and the diffractive optical element 27 are fixed on the inner housing 21 and the outer housing 20, respectively, such that the collimating optical element 26 is located between the substrate 22 and the diffractive optical element 27 in the vertical direction.

[0097] Furthermore, in the preferred embodiment, the laser unit 23 is a side-firing laser unit. When the laser unit 23 receives power, the laser unit 23 can provide a plurality of laser beams L2. The laser beams L2 travel toward the reflective optical element 25 and are reflected by the reflective optical element 25 toward the collimating optical element 26 and the diffractive optical element 27. The collimating optical element 26 collimates the laser beams L2 reflected by the reflective optical element 25 so that the laser beams L2 passing through the collimating optical element 26 are incident on the diffractive optical element 27 in a preferred direction. The diffractive optical element 27 reshapes the laser beams L2 passing through the collimating optical element 26 so that the laser beams L2 form structured light and are projected outward.

[0098] Next, the active alignment system of the present application is described. Please refer to Figure 5 , which is a block diagram of a preferred embodiment of the active alignment system of the present application. The active alignment system 3 comprises a first sensing unit 31, a second sensing unit 32, a positioning unit 33, and a control unit 34, and the control unit 34 is electrically connected between the first sensing unit 31, the second sensing unit 32, and the positioning unit 33. The positioning unit 33 is used to move the optical element (e.g. the collimating optical element 26 or the diffractive optical element 27), and the first sensing unit 31 is used to sense the measured pattern of the laser beam passing through the optical element, while the second sensing unit 32 is used to take pictures of the optical element.

[0099] Furthermore, during the assembly of the laser module 2, the control unit 34 first drives the positioning unit 33 to move the optical element according to the results of the pictures taken by the second sensing unit 32, so that the optical element is located at a standard position and in a standard posture, thereby completing the preliminary coarse positioning. Then, the control unit 34 drives the positioning unit 33 to move the optical element according to the measured pattern obtained by the first sensing unit 31 until the measured pattern meets a detection standard, thereby completing the fine positioning for the subsequent fixing procedure.

[0100] The assembly process of the laser module 2 is described in detail below. Please refer to Figure 6A and Figure 6B , Figure 6A is a first stage implementation concept diagram for assembling the collimating optical element to the inner housing using the active alignment system shown in Figure 5 Figure 6B is a second stage implementation concept diagram for assembling the collimating optical element to the inner housing using the active alignment system shown in Figure 5 In the preferred embodiment, the second sensing unit 32 comprises three cameras 325, and the positioning unit 33 comprises a six-axis positioning unit 334 capable of moving the collimating optical element 26 in six axes. However, the implementation form and number of the second sensing unit 32 and the positioning unit 33 are not limited to the above.

[0101] Figure 6A ​The diagram illustrates the first stage of assembling the collimating optical element 26 onto the inner housing 21 using the active alignment system 3. The six-axis positioning unit 334 first moves the collimating optical element 26 between the three cameras 325, positioning the cameras 325 below, behind, and to the side of the collimating optical element 26, respectively. Then, the cameras 325 capture images of the collimating optical element 26, and the images are transmitted back to the control unit 34. The control unit 34 receives relevant control feedback and drives the six-axis positioning unit 334 to move the collimating optical element 26 until it is positioned at a predetermined location with a system-defined reference standard and in a predetermined posture (e.g., angular posture). In this preferred embodiment, the lower camera 325 is used to confirm the position of the collimating optical element 26 in the XY plane, while the rear and side cameras 325 are used to confirm the flatness of the collimating optical element 26.

[0102] Figure 6B The diagram illustrates that during the second stage of the active alignment system 3 assembling the collimating optical element 26 onto the inner housing 21, a camera 326 positioned above the collimating optical element 26 is used to capture images of the collimating optical element 26 and the inner housing 21. The images captured by the camera 326 are transmitted back to the control unit 34, which receives relevant control feedback and drives the six-axis positioning unit 334 to move the collimating optical element 26 until the collimating optical element 26 is aligned with the inner housing 21 and placed on the inner housing 21.

[0103] Among them, in the above Figure 6A and Figure 6B Before the active alignment system 3 positions the collimating optical element 26 onto the inner housing 21, the collimating optical element 26 or the inner housing 21 is first coated with adhesive to create an adhesive layer on it. Figure 6A and Figure 6B After the active alignment system 3 positions the collimating optical element 26 onto the inner housing 21, the adhesive is then cured (e.g., by UV curing) to fix the collimating optical element 26 onto the inner housing 21.

[0104] Please see Figure 7A and Figure 7B , Figure 7A To utilize Figure 5 The diagram illustrates a preferred embodiment of an active alignment system for coarse positioning of an aligned optical element. Figure 7B To utilize Figure 5A preferred embodiment of the active alignment system for fine positioning and assembling the collimating optical element to the laser module is shown in FIG. 3. In this preferred embodiment, the first sensing unit 31 comprises a beam profiler 311, the second sensing unit 32 comprises three cameras 321, and the positioning unit 33 comprises a six-axis positioning unit 331 capable of moving the collimating optical element 26 in six axes. Since the collimating optical element 26 has been assembled to the inner housing 21, in this preferred embodiment, the six-axis positioning unit 331 moves the collimating optical element 26 by moving the inner housing 21. However, the implementation and number of the first sensing unit 31, the second sensing unit 32, and the positioning unit 33 are not limited to the above.

[0105] Figure 7A In the coarse positioning process of the collimating optical element 26 by the active alignment system 3, the six-axis positioning unit 331 first moves the inner housing 21 and the collimating optical element 26 fixed thereto to the vicinity of the three cameras 321, so that the three cameras 321 are located above, behind, and beside the collimating optical element 26, respectively. Then, the cameras 321 take pictures of the inner housing 21 and the collimating optical element 26 fixed thereto, and the pictures are sent back to the control unit 34, so that the control unit 34 obtains the relevant control feedback and drives the six-axis positioning unit 331 to move the inner housing 21 and the collimating optical element 26 fixed thereto until the inner housing 21 and the collimating optical element 26 fixed thereto are located at the standard position and in the standard attitude (e.g. angular attitude) with the laser unit 23 as the positioning reference. At this point, the coarse positioning process is completed. In this preferred embodiment, the camera 321 above is used to confirm the position of the inner housing 21 and the collimating optical element 26 fixed thereto in the XY plane, and the cameras 321 behind and beside are used to confirm the flatness of the inner housing 21 and the collimating optical element 26 fixed thereto.

[0106] Figure 7BAs shown in the fine positioning process of the collimating optical element 26 by the active alignment system 3, the beam profiler 311 is disposed adjacent to the laser module 2, and the control unit 34 drives the power unit 35 electrically connected thereto to provide power to the laser module 2, so that the laser unit 23 provides the laser beam L2. After the laser beam L2 travels through the collimating optical element 26 by reflection of the reflecting optical element 25, the beam profiler 311 disposed above the collimating optical element 26 senses the measured pattern I1 of the laser beam L2 passing through the collimating optical element 26, and the control unit 34 drives the six-axis positioning unit 331 to move the inner housing 21 and the collimating optical element 26 fixed thereon according to the measured pattern I1 until the measured pattern I1 sensed by the beam profiler 311 meets the detection standard. When the measured pattern I1 meets the detection standard, it means that the collimating optical element 26 is located at the in-focus position and attitude, and the subsequent process of fixing the inner housing 21 can be prepared.

[0107] Further, as shown in the above Figure 7A and Figure 7B , before the active alignment system 3 positions the inner housing 21 and the collimating optical element 26 thereon to the laser module 2, the inner housing 21 or the substrate 22 is first subjected to a glue application process to have glue on the inner housing 21 or the substrate 22, and after Figure 7A and Figure 7B , the active alignment system 3 positions the inner housing 21 and the collimating optical element 26 thereon to the laser module 2, the glue is then subjected to a curing process (such as ultraviolet curing process) to fix the inner housing 21 to the laser module 2.

[0108] In addition, the detection standard of the measured pattern I2 for positioning the collimating optical element 26 is further described as follows. Please refer to Figure 8A and Figure 8B , Figure 8A , which is a preferred conceptual diagram of the measured pattern when the collimating optical element is located at the out-of-focus position and attitude, Figure 8B , which is a preferred conceptual diagram of the measured pattern when the collimating optical element is located at the in-focus position and attitude. As shown in Figure 8A and Figure 8BAs shown, the size, shape, and position of the light spot in the tested pattern I1 will change depending on the position and orientation of the collimating optical element 26. Therefore, in this preferred embodiment, the detection criteria include a light spot size detection criterion, a light spot shape detection criterion, and / or a light spot position detection criterion. By detecting the size, shape, and / or position of the light spot in the tested pattern I1, it can be used as a basis for determining whether the collimating optical element 26 is located in the collimated position and orientation. However, the design of the detection criteria is not limited to the above, and those skilled in the art can make any equivalent design changes according to actual application needs.

[0109] Please see Figure 9A and Figure 9B , Figure 9A To utilize Figure 5 The diagram shows a conceptual illustration of the first stage of an active alignment system assembling diffractive optical elements onto a housing. Figure 9B To utilize Figure 5 The diagram illustrates a second-stage implementation concept of the active alignment system assembling the diffractive optical element onto the housing. In this preferred embodiment, the second sensing unit 32 includes three cameras 322, and the positioning unit 33 includes a six-axis positioning unit 332 capable of six-axis movement of the diffractive optical element 27. However, the implementation and number of the second sensing unit 32 and the positioning unit 33 are not limited to those described above.

[0110] Figure 9A The diagram illustrates the first stage of assembling the diffractive optical element 27 onto the housing 20 using the active alignment system 3. The six-axis positioning unit 332 first moves the diffractive optical element 27 between the three cameras 322, positioning the cameras 322 below, behind, and to the side of the diffractive optical element 27, respectively. Then, the cameras 322 capture images of the diffractive optical element 27, and the images are transmitted back to the control unit 34. The control unit 34 receives relevant control feedback and drives the six-axis positioning unit 332 to move the diffractive optical element 27 until it is positioned at a predetermined location with a system-defined reference standard and in a predetermined orientation (e.g., angular orientation). In this preferred embodiment, the lower camera 322 is used to confirm the position of the diffractive optical element 27 in the XY plane, while the rear and side cameras 322 are used to confirm the flatness of the diffractive optical element 27.

[0111] Figure 9BThe diagram illustrates that during the second stage of the active alignment system assembling the diffractive optical element 27 onto the housing 20, a camera 323 positioned above the diffractive optical element 27 is used to capture images of the diffractive optical element 27 and the housing 20. The image captured by the camera 323 is transmitted back to the control unit 34, which receives relevant control feedback and drives the six-axis positioning unit 332 to move the diffractive optical element 27 until the diffractive optical element 27 is aligned with the housing 20 and placed on the housing 20.

[0112] Among them, in the above Figure 9A and Figure 9B Before the active alignment system 3 positions the diffractive optical element 27 onto the housing 20, the diffractive optical element 27 or the housing 20 is first coated with adhesive to create an adhesive layer on it. Figure 9A and Figure 9B After the active alignment system 3 positions the diffractive optical element 27 onto the housing 20, the adhesive is then cured (e.g., by ultraviolet curing) to fix the diffractive optical element 27 onto the housing 20.

[0113] Please see Figure 10A and Figure 10B , Figure 10A To utilize Figure 5 The diagram illustrates a preferred embodiment of an active alignment system for coarsely positioning diffractive optical elements. Figure 10B To utilize Figure 5 The diagram illustrates a preferred embodiment of an active alignment system for fine-tuning and assembling diffractive optical elements into a laser module. In this preferred embodiment, the first sensing unit 31 includes a camera module 312 and a projection surface 313, the second sensing unit 32 includes three cameras 324, and the positioning unit 33 includes a six-axis positioning unit 333 capable of six-axis movement of the diffractive optical element 27. Since the diffractive optical element 27 has already been assembled onto the housing 20, in this preferred embodiment, the six-axis positioning unit 333 moves the diffractive optical element 27 by moving the housing 20. However, the implementation and number of the first sensing unit 31, the second sensing unit 32, and the positioning unit 33 are not limited to those described above.

[0114] Figure 10AIn the process of performing the coarse positioning of the diffractive optical element 27 by the active alignment system 3, the six-axis positioning unit 333 first moves the outer housing 20 and the diffractive optical element 27 fixed thereon to be adjacent to the three cameras 324 above, behind and on the side of the diffractive optical element 27, respectively. Then, the cameras 324 take pictures of the outer housing 20 and the diffractive optical element 27 fixed thereon, respectively. The pictures taken by the cameras 324 are transmitted to the control unit 34, so that the control unit 34 obtains the relevant control feedback and drives the six-axis positioning unit 333 to move the outer housing 20 and the diffractive optical element 27 fixed thereon until the outer housing 20 and the diffractive optical element 27 fixed thereon are located at the standard position with the inner housing 21 and / or the collimating optical element 26 as the positioning reference and are in the standard attitude (e.g. angular attitude), thereby completing the coarse positioning process. In the preferred embodiment, the camera 324 above is used to confirm the position of the outer housing 20 and the diffractive optical element 27 fixed thereon in the XY plane, while the cameras 324 behind and on the side are used to confirm the flatness of the outer housing 20 and the diffractive optical element 27 fixed thereon.

[0115] Preferably, but not exclusively, the active alignment system 3 further comprises one or more mirror elements 36 located adjacent to the outer housing 20 and used to image at least part of the outer housing 20. When the cameras 324 take pictures of the outer housing 20 and the mirror elements 36 adjacent thereto, the control unit 34 can further perform housing surface analysis on the outer housing 20 according to the pictures taken by the cameras 324, so as to determine whether the outer housing 20 is scratched or damaged.

[0116] Figure 10BThe diagram illustrates that during the fine-tuning and positioning of the diffractive optical element 27 by the active alignment system 3, the camera module 312 and the projection surface 313 are positioned above and near the laser module 2, with the projection surface 313 located between the diffractive optical element 27 and the camera module 312. The control unit 34 drives the electrically connected power unit 35 to provide power to the laser module 2, causing the laser unit 23 to provide a laser beam L2. The laser beam L2 travels towards the collimating optical element 26 and the diffractive optical element 27 after being reflected by the reflecting optical element 25, and sequentially passes through the collimating optical element 26. After the structured light is formed by the diffractive optical element 27, the camera module 312 located above the projection surface 313 will capture the structured light projected onto the projection surface 313 to obtain the test pattern I2. The control unit 34 then drives the six-axis positioning unit 333 to move the housing 20 and the diffractive optical element 27 fixed thereon according to the test pattern I2 until the test pattern I2 obtained by the camera module 312 meets the detection standard. When the test pattern I2 meets the detection standard, it means that the diffractive optical element 27 is in the collimated position and orientation, and the subsequent procedure of fixing the housing 20 can be prepared.

[0117] Furthermore, regarding the above Figure 10A and Figure 10B Before the active alignment system 3 positions the housing 20 and its diffractive optical elements 27 to the laser module 2, the housing 20 or substrate 22 is first coated with adhesive to create an adhesive layer on it. Figure 10A and Figure 10B After the active alignment system 3 positions the housing 20 and its diffractive optical element 27 onto the laser module 2, the adhesive is then cured (such as by ultraviolet curing) to fix the housing 20 onto the laser module 2.

[0118] Furthermore, the testing criteria for the test pattern I2 used to position the diffractive optical element 27 are further explained below. Please refer to... Figure 11, which is a preferred conceptual diagram of the test pattern when the DOE is located at the in-focus position and attitude. In the diagram, the contrast, field of illumination, hot spot, pattern angle, power uniformity, geometrical & pattern mass center, performance of the zero order light beam, and dot count of the test pattern I2 are all changed according to the position and attitude of the DOE 27. Therefore, in the preferred embodiment, the detection criteria include the number detection criterion, the contrast detection criterion, the field of illumination detection criterion, the hot spot detection criterion, the pattern angle detection criterion, the zero order light beam detection criterion, the power uniformity detection criterion, and / or the geometrical & pattern mass center detection criterion. The detection of the contrast, field of illumination, hot spot, pattern angle, power uniformity, geometrical & pattern mass center, performance of the zero order light beam, and / or dot count of the test pattern I2 can be used as the basis for determining whether the DOE 27 is located at the in-focus position and attitude. However, the design of the detection criteria is not limited to the above, and any equivalent changes can be made according to the actual application requirements by those skilled in the art.

[0119] In summary, the present application provides an active alignment method for assembling a laser module as shown in Figure 12 . The active alignment method includes: step S11, obtaining a test pattern by sensing a laser beam passing through an optical lens; and step S12, moving the optical lens according to the test pattern until the test pattern meets the detection criteria.

[0120] In the preferred embodiment, the active alignment method for assembling a laser module 2 of the present application can be further represented as shown in Figure 13A and Figure 13B . The active alignment method includes:

[0121] Step S201, photographing the collimating optical element 26 using at least three cameras 325, and the cameras 325 are located in different directions of the collimating optical element 26;

[0122] Step S202, moving the collimating optical element 26 using the six-axis positioning unit 334 according to the photographing results of step S201 until the collimating optical element 26 is located at a predetermined position and in a predetermined attitude with a system self-defined reference standard as the positioning reference;

[0123] Step S203, taking a picture of the collimating optical element 26 and the inner housing 21 by using the camera 326;

[0124] Step S204, moving the collimating optical element 26 according to the picture taken in step S203, so that the collimating optical element 26 is aligned with and placed on the inner housing 21;

[0125] Step S205, taking a picture of the inner housing 21 and the collimating optical element 26 fixed thereon by using at least three cameras 321, which are respectively located in different directions of the collimating optical element 26;

[0126] Step S206, moving the inner housing 21 and the collimating optical element 26 fixed thereon according to the picture taken in step S205 by using the six-axis positioning unit 331, until the inner housing 21 and the collimating optical element 26 fixed thereon are located in a standard position and a standard attitude with the position of the laser unit 23 as a positioning reference;

[0127] Step S207, obtaining a measured pattern I1 by using the beam profiler 311 to sense the laser beam L2 passing through the collimating optical element 26;

[0128] Step S208, moving the inner housing 21 and the collimating optical element 26 fixed thereon according to the measured pattern I1 obtained in step S207, until the measured pattern I1 meets a detection standard for positioning the collimating optical element 26;

[0129] Step S209, taking a picture of the diffractive optical element 27 by using at least three cameras 322, which are respectively located in different directions of the diffractive optical element 27;

[0130] Step S210, moving the diffractive optical element 27 according to the picture taken in step S209 by using the six-axis positioning unit 332, until the diffractive optical element 27 is located in a predetermined position and a predetermined attitude with a system self-defined reference standard as a positioning reference;

[0131] Step S211, taking a picture of the diffractive optical element 27 and the outer housing 20 by using the camera 323;

[0132] Step S212, moving the diffractive optical element 27 according to the picture taken in step S211, so that the diffractive optical element 27 is aligned with and placed on the outer housing 20;

[0133] Step S213, taking a picture of the outer housing 20 and the diffractive optical element 27 fixed thereon by using at least three cameras 324, which are respectively located in different directions of the diffractive optical element 27;

[0134] Step S214, the outer housing 20 and the diffractive optical element 27 fixed thereon are moved by the six-axis positioning unit 333 according to the shooting result of step S213 until the outer housing 20 and the diffractive optical element 27 fixed thereon are located at a standard position with the inner housing 21 and / or the collimating optical element 26 as the positioning reference and are in a standard attitude;

[0135] Step S215, when the laser beam L2 passes through the diffractive optical element 27 to form a structured light and is projected to the projection surface 313, the camera module 312 is used to take a picture to obtain a measured pattern I2; and

[0136] Step S216, the outer housing 20 and the diffractive optical element 27 fixed thereon are moved according to the measured pattern I2 obtained in step S215 until the measured pattern I2 meets the detection standard for positioning the diffractive optical element 27.

[0137] It is particularly noted that, compared with the background art, the present application uses an optical active alignment method to position and correct the position and attitude of the optical lens during the assembly of the laser module, which can greatly improve the assembly precision to the nanometer level and reduce the assembly cost, and is suitable for mass production. Further, please refer to Figure 14 , which is a schematic diagram of the relative relationship between the positioning tolerance of optical positioning and mechanical positioning and the assembly cost. Figure 14 It is shown that when the positioning tolerance is below 0.025 mm, the cost required for optical positioning is more than 10% lower than that required for mechanical positioning.

[0138] In addition, although the above description takes the laser module with an edge-shooting type laser unit, a reflective optical element, a collimating optical element and a diffractive optical element as an example, the laser module assembled by the active alignment system and the active alignment method of the present application is not limited to the above, and those skilled in the art can apply it to assemble various embodiments of the laser module according to the actual situation through the inspiration obtained from the above embodiments.

[0139] For example, please refer to Figure 15Fig. 4 is a cross-sectional conceptual diagram of a partial structure of a laser module 4 in a preferred embodiment of the application, which is assembled by using the active alignment system and the active alignment method of the application. The laser module 4 includes a laser unit 41, a projection structure 42, and a diffractive optical element 43. The laser unit 41 is a vertical cavity surface emitting laser (VCSEL), and the projection structure 42 is disposed between the laser unit 41 and the diffractive optical element 43 and has at least one optical lens (not shown). When the laser unit 41 receives power, the laser unit 41 can provide a plurality of laser beams L3, which travel toward the projection structure 42, are guided by the optical lens, and then travel toward the diffractive optical element 43. Finally, the laser beams L3 form structured light after passing through the diffractive optical element 43 and are projected outward.

[0140] Similarly, during the assembly of the laser module 4, the projection structure 42 and / or the optical lens therein can be positioned relative to the laser unit 41 by using the active alignment system and the active alignment method of the application, and the diffractive optical element 45 can be positioned relative to the projection structure 42 and / or the optical lens therein by using the active alignment system and the active alignment method of the application. Thus, the assembly precision of the laser module 4 can be greatly improved, and the assembly cost can be reduced.

[0141] The above description is only the preferred embodiments of the application and is not intended to limit the scope of the claims of the application. Therefore, any equivalent changes or modifications made without departing from the spirit of the application should be included in the scope of the claims of the application.

Claims

1. An active alignment system for assembling a laser module, the laser module comprising at least one optical lens and a laser unit, and a laser beam generated by the laser unit being projected outwardly after passing through the at least one optical lens, characterized in that, The active alignment system comprises: a positioning unit for moving the at least one optical element; a first sensing unit for sensing a measured pattern of the laser beam passing through the at least one optical element; and a control unit electrically connected between the positioning unit and the first sensing unit for driving the positioning unit to move the at least one optical element until the measured pattern meets a detection criterion according to the measured pattern. The active alignment system further comprises a second sensing unit having a plurality of cameras, the cameras being respectively located in different directions of the at least one optical element, the second sensing unit being electrically connected to the control unit and being used to take pictures of the at least one optical element before the first sensing unit is used to sense the measured pattern of the laser beam passing through the at least one optical element, wherein the control unit is further used to drive the positioning unit to move the at least one optical element to a standard position and a standard posture according to a picture taken by the second sensing unit.

2. The active alignment system of claim 1, wherein, The laser module further comprises a reflective optical element, and the laser unit is a side-emitting laser unit, wherein the reflective optical element is used to reflect the laser beam generated by the side-emitting laser unit so that the laser beam travels in the direction of the at least one optical element; or the laser unit is a vertical cavity surface emitting laser unit, and the laser beam generated by the vertical cavity surface emitting laser unit travels in the direction of the at least one optical element.

3. The active alignment system of claim 1, wherein, The positioning unit is a six-axis positioning unit.

4. The active alignment system of claim 1, wherein, The at least one optical element comprises a collimating optical element, and the collimating optical element is used to collimate the laser beam passing through the collimating optical element.

5. The active alignment system of claim 4, wherein, The detection criterion comprises a light spot size detection criterion, a light spot shape detection criterion, and / or a light spot position detection criterion.

6. The active alignment system of claim 4, wherein, The first sensing unit is a beam profiler.

7. The active alignment system of claim 4, wherein, The laser module further comprises an inner housing, and the inner housing is used to accommodate the collimating optical element, wherein the positioning unit moves the collimating optical element by moving the inner housing.

8. The active alignment system of claim 4, wherein, The second sensing unit is used to take pictures of the collimating optical element, and the control unit is further used to drive the positioning unit to move the collimating optical element to the standard position and the standard posture with the laser unit as the positioning reference according to the picture taken by the second sensing unit.

9. The active alignment system of claim 8, wherein, The laser module further comprises an inner housing, and the inner housing is used to accommodate the collimating optical element, wherein the positioning unit moves the collimating optical element by moving the inner housing.

10. The active alignment system of claim 9, wherein, The collimating optical element is first moved by the positioning unit to a predetermined position and a predetermined posture with a system self-defined reference criterion as the positioning reference, and then placed on the inner housing by the positioning unit.

11. The active alignment system of claim 8, wherein, The second sensing unit comprises at least three cameras, and the at least three cameras are respectively located in different directions of the collimating optical element.

12. The active alignment system of claim 1, wherein, The at least one optical element comprises a diffractive optical element for beam shaping the laser beam passing therethrough so that the laser beam forms a structured light.

13. The active alignment system of claim 12, wherein, The detection criteria include a feature point quantity detection criterion, a contrast detection criterion, an illumination field of view detection criterion, a hot spot detection criterion, a pattern angle detection criterion, a zero-order beam detection criterion, an energy uniformity detection criterion, and / or a geometric and pattern barycenter position detection criterion.

14. The active alignment system of claim 12, wherein The first sensing unit includes a projection surface and an image capture module, and the projection surface is disposed between the diffractive optical element and the image capture module; wherein the image capture module captures an image when the structured light is projected onto the projection surface to obtain the measured pattern.

15. The active alignment system of claim 12, wherein, The laser module further includes an outer housing, and the outer housing is used to dispose the diffractive optical element thereon; wherein the positioning unit moves the diffractive optical element by moving the outer housing.

16. The active alignment system of claim 12, wherein, The second sensing unit is used to capture the diffractive optical element, and the control unit is further used to drive the positioning unit to move the diffractive optical element to the standard position and the standard posture according to the capturing result of the second sensing unit.

17. The active alignment system of claim 16, wherein, The at least one optical lens further includes a collimating optical element disposed below the diffractive optical element, and the laser module further includes an inner housing used to dispose the collimating optical element thereon; wherein the control unit is used to drive the positioning unit to move the diffractive optical element to the standard position and the standard posture with the inner housing and / or the collimating optical element as the positioning reference according to the capturing result of the second sensing unit.

18. The active alignment system of claim 16, wherein, The second sensing unit includes at least three cameras, and the at least three cameras are respectively located in different directions of the diffractive optical element.

19. The active alignment system of claim 16, wherein, The laser module further includes an outer housing, and the outer housing is used to dispose the diffractive optical element thereon; wherein the positioning unit moves the diffractive optical element by moving the outer housing.

20. The active alignment system of claim 19, wherein, The second sensing unit captures the outer housing for subsequent shell surface analysis.

21. The active alignment system of claim 19, wherein, The active alignment system further includes at least one mirror element, and the at least one mirror element is disposed adjacent to the outer housing; wherein the second sensing unit captures the outer housing and / or the at least one mirror element for subsequent shell surface analysis.

22. The active alignment system of claim 19, wherein, The diffractive optical element is first moved by the positioning unit to a predetermined position and a predetermined posture with a system self-defined reference standard as the positioning reference, and then placed on the outer housing by the positioning unit.

23. An active alignment method for assembling a laser module, the laser module comprising at least one optical lens and a laser unit, wherein a laser beam generated by the laser unit is projected outward after passing through the at least one optical lens, characterized in that, The active alignment method includes: (a) capturing the at least one optical lens by using a plurality of cameras, and the cameras are respectively located in different directions of the at least one optical lens; (b) moving the at least one optical lens until the at least one optical lens is located in a standard position and a standard posture according to a capturing result obtained in step (a); (c) sensing a measured pattern obtained by the laser beam passing through the at least one optical lens; and (d) moving the at least one optical lens until the measured pattern meets a detection criterion according to the measured pattern.

24. The active alignment method of claim 23, wherein, The laser module further comprises a reflective optical element, and the laser unit is a side-firing laser unit, wherein the reflective optical element is used to reflect the laser beam generated by the side-firing laser unit so that the laser beam travels toward the direction of the at least one optical lens; or the laser unit is a vertical-cavity surface-emitting laser unit, and the laser beam generated by the vertical-cavity surface-emitting laser unit travels toward the direction of the at least one optical lens.

25. The active alignment method of claim 23, wherein, The step (d) comprises moving the at least one optical lens by using a six-axis positioning unit.

26. The active alignment method of claim 23, wherein, The at least one optical lens comprises a collimating optical element, and the collimating optical element is used to collimate the laser beam passing through the collimating optical element.

27. The active alignment method of claim 26, wherein, The detection criteria comprise a light spot size detection criterion, a light spot shape detection criterion, and / or a light spot position detection criterion.

28. The active alignment method of claim 26, wherein, The step (c) comprises sensing the laser beam passing through the collimating optical element by using a beam profiler.

29. The active alignment method of claim 26, wherein, The laser module further comprises an inner housing, and the inner housing is used to accommodate the collimating optical element; wherein in the step (d), the collimating optical element is moved by moving the inner housing.

30. The active alignment method of claim 26, wherein, The step (a) comprises: photographing the collimating optical element by using a plurality of cameras, and the cameras are respectively located at different directions of the collimating optical element; and / or The step (b) comprises: moving the collimating optical element according to the photographing result obtained in the step (a) until the collimating optical element is located at the standard position and is in the standard attitude with the location of the laser unit as the positioning reference.

31. The active alignment method of claim 30, wherein, The step (a) comprises photographing the collimating optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element; and / or The step (b) comprises moving the collimating optical element by using a six-axis positioning unit.

32. The active alignment method of claim 30, wherein, The laser module further comprises an inner housing, and the inner housing is used to accommodate the collimating optical element; wherein in the step (b), the collimating optical element is moved by moving the inner housing.

33. The active alignment method of claim 32, wherein, The active alignment method further comprises, before the step (a): (e1) photographing the collimating optical element; (e2) moving the collimating optical element according to a photographing result obtained in the step (e1) until the collimating optical element is located at a predetermined position and is in a predetermined attitude with a system self-defined reference standard as the positioning reference; (e3) photographing the collimating optical element and the inner housing; and (e4) moving the collimating optical element according to a photographing result obtained in the step (e3) so that the collimating optical element is aligned with and placed on the inner housing.

34. The active alignment method of claim 33, wherein, The step (e1) comprises photographing the collimating optical element by using at least three cameras, and the at least three cameras are respectively located at different directions of the collimating optical element.

35. The active alignment method of claim 33, wherein, The step (e2) and / or the step (e4) comprises moving the collimating optical element by using a six-axis positioning unit.

36. The active alignment method of claim 23, wherein, The at least one optical lens comprises a diffractive optical element, which is used to perform beam shaping on the laser beam passing therethrough so that the laser beam forms a structured light.

37. The active alignment method of claim 36, wherein, The detection criteria include a feature point quantity detection criterion, a contrast detection criterion, an illumination field detection criterion, a hot spot detection criterion, a pattern angle detection criterion, a zero-order beam detection criterion, an energy uniformity detection criterion, and / or a geometric and pattern barycenter position detection criterion.

38. The active alignment method of claim 36, wherein, The step (c) includes: capturing the DOE by using a camera module when the structured light is projected to a projection surface to obtain the measured pattern.

39. The active alignment method of claim 36, wherein, The laser module further includes an outer housing, and the DOE is disposed on the outer housing; in the step (d), the DOE is moved by moving the outer housing.

40. The active alignment method of claim 36, wherein, The step (a) includes: The DOE is captured by using a plurality of cameras, and the cameras are respectively located at different directions of the DOE; and / or The step (b) includes: The DOE is moved according to the capturing result obtained in the step (a) until the DOE is located at the standard position and in the standard posture.

41. The active alignment method of claim 40, wherein, The at least one optical lens further includes a collimating optical element located below the DOE, and the laser module further includes an inner housing for disposing the collimating optical element thereon; in the step (b), the DOE is moved according to the capturing result until the DOE is located at the standard position with the inner housing and / or the collimating optical element as the positioning reference and in the standard posture.

42. The active alignment method of claim 40, wherein, The step (a) includes: the DOE is captured by using at least three cameras, and the at least three cameras are respectively located at different directions of the DOE; and / or The step (b) includes: the DOE is moved by using a six-axis positioning unit.

43. The active alignment method of claim 40, wherein, The laser module further includes an outer housing, and the DOE is disposed on the outer housing; in the step (b), the DOE is moved by moving the outer housing.

44. The active alignment method of claim 43, wherein, The active alignment method further includes, before the step (a): (f1) capturing the DOE; (f2) moving the DOE according to a capturing result obtained in the step (f1) until the DOE is located at a predetermined position with a system self-defined reference standard as the positioning reference and in a predetermined posture; (f3) capturing the DOE and the outer housing; and (f4) moving the DOE according to a capturing result obtained in the step (f3) to align the DOE with the outer housing and dispose the DOE on the outer housing.

45. The active alignment method of claim 44, wherein, The step (f1) includes: the DOE is captured by using at least three cameras, and the at least three cameras are respectively located at different directions of the DOE.

46. The active alignment method of claim 44, wherein, The step (f2) and / or the step (f4) includes: the DOE is moved by using a six-axis positioning unit.

47. The active alignment method of claim 23, wherein, The active alignment method further includes, before the step (c): performing a gluing operation, and further includes, after the step (d): performing a curing procedure on the glue disposed in the gluing operation.

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